This proposal requests funds to assist in the support of the seventh biennial Gordon Research Conference on Mammary Gland Biology to be held in New London, New Hampshire, June 12-17, 1983. This highly successful series is designed to bring together, for a week of informal discussion and inquiry, biologists for a wide spectrum of subfields who share a major research interest in the mammary gland. New data and ideas to be presented in scheduled sessions will concern: structure and evolution of the milk protein genes; hormonal requirements for expression of the milk protein genes; mechanisms involved in metastases; the extracellular matrix and cytokeratins in mammary tissue; membrane dynamics and receptor function in mammary tissue; cells in milk; the Golgi apparatus and microtubules; vitamin D metabolism in reproduction and lactation; and biological effects of estrogens on the mammary gland. The 1981 conference was rated as one of the very best conferences by participants and Gordon Conference monitors. The success of this conference rests on the multidisciplinary mixture of participants, and the critical role of the speakers and discussion leaders in catalyzing active interchange of ideas, facts, methods and arguments. The scientists we have invited to assume this role for the 1983 conference are eminently capable of filling it. We need adequate funding to enable them to participate.